An exhaust gas recirculation system may be used to reduce the generation of undesirable pollutant gases during the operation of internal combustion engines. Exhaust gas recirculation systems generally recirculate exhaust gas generated during the combustion process into the intake air supply of the internal combustion engine. The exhaust gas introduced into the engine cylinders displaces a volume of the intake air supply that would otherwise be available for oxygen. Reduced oxygen concentrations lower the maximum combustion temperatures within the cylinders and slow the chemical reactions of the combustion process, which decreases the formation of oxides of nitrogen (NOx).
Many internal combustion engines having such an exhaust gas recirculation system also have one or more turbochargers. Exhaust gas from the combustion cylinders is typically used to drive the turbine of the turbocharger which, in turn, drives the compressor of the turbocharger to compress fluid that is subsequently supplied to the combustion cylinders. A portion of the exhaust gas may also be diverted from the exhaust system used to drive the turbocharger and into the exhaust gas recirculation system.
U.S. Patent Publication No. US 2010/0024416 A1 discloses an internal combustion engine having a pair of cylinder banks with an exhaust gas recirculation system and a turbocharger associated with each cylinder bank. The exhaust gas recirculation is fluidly connected to one of the exhaust manifolds and results in less exhaust gas flowing through that manifold toward its associated turbocharger. The turbochargers are sized differently to account for differences in exhaust gas flow through the exhaust manifolds associated with each cylinder bank. A balance passageway may be provided to selectively allow exhaust gas to pass from one exhaust manifold to the other exhaust manifold.
The foregoing background discussion is intended solely to aid the reader. It is not intended to limit the innovations described herein nor to limit or expand the prior art discussed. Thus the foregoing discussion should not be taken to indicate that any particular element of a prior system is unsuitable for use with the innovations described herein, nor is it intended to indicate any element, including solving the motivating problem, to be essential in implementing the innovations described herein. The implementations and application of the innovations described herein are defined by the appended claims.